Abstract: In this paper,a new method of the information theoretic approach is applied to optimize the solution on the problem of completing the coverage of target area with the minimum number of sensors.Source coding theorems from information theory is utilized to calculate a lower bound and then determine the minimum number of sensors under the condition that WSN must accurately estimates the features of some phenomenon by utilizing the measurements of sensors. Simulation results show that information theoretic approach outperforms information coverage with less sensor quatity and more coverage rationality,especially under the condition of correct probability of event estimation and the design of sensor distribution,there is a efficient optimization and reference value.